Apple Certified Support Professional

Generally, the material is updated with each OS release. If prior patterns hold, you can expect materials related to Sequoia to start showing up around the new year. Please note, it is widely believed that this year's materials may be a little later due to the staggered release of Sequoia's features. This is speculation as but is inline with prior years when some features were delayed.

As VikingOSX states, we are community members. However, Apple can be a creature of habit. With the annual OS release expected every Sept/Oct, the certification material updates are usually a few months behind.

There is no one from Apple here that can answer that question. These are strictly user-supported public communities and no Apple employees participate here.